In the article about focal points and focal areas I underlined the importance of creating a center of interest in your artwork. The question that I want to answer in this article is the following: where to put the center of interest on your drawing sheet? One possible approach is the famous rule of thirds. Basically, given a rectangular sheet placed horizontally or vertically, I divide each side into three parts and join them as reported by the following figure.
Photo from http://www.williampolito.com
You can put the center of interest of your image in the intersection points of these segments (highlighted by circles). This is a simple composition rule that is a simplification of the famous golden section. This rule is also used in photography and the next time you go on vacation you can use it in your photos. It will be sufficient to decide what is most interesting area of your subject and place it on the points mentioned above. Below I reported an example of image taken using this rule. Notice how the bow of the boat has been placed on the intersection at the bottom left.
Photo from http://www.smashandpeas.com